The intravenous catheter apparatus is used to inject medicines, glucose and other nourishment, in liquid form, into the blood stream of patients during their treatment. Such intravenous catheter apparatuses are known from the prior art and permit the inlet of different media flow during the treatment of the patient. After the needle along with a flexible catheter is inserted in the vein of the patient and blood flashes in the catheter, the needle is withdrawn from the vein. The flexible catheter portion continues to remain in the vein to inject medicines, glucose and other nourishment in liquid form into the blood stream. The needle is disposed of after withdrawal from the catheter and the vein. If the used needle is not covered with some protection, it can prick anyone who comes into contact with the needle, including medical professionals and people in charge of disposal of hospital waste. Accidental pricking by used needles is very dangerous and at times even fatal if the needle has come into contact with the blood of an ill patient. Accidental pricking may spread blood borne diseases like Hepatitis B, AIDS, etc. In view of the foregoing, a safety device is essential to completely cover the tip of the needle after use and while disposing it to thereby prevent contact with the needle.
The prior art acknowledges the need for a needle tip guard placed upon the needle after it's been withdrawn from the catheter. For example, U.S. Pat. No. 5,135,504 uses a needle safety device in which a “retaining ring” is fitted inside the intravenous catheter apparatus and the “needle guard” slides inside the retaining ring. This device has some of the following disadvantages: 1) the retaining ring remains inside the main body during use of the apparatus which hinders flow of solutions through it, 2) there is a likelihood that guard jaws which cover the needle tip may open so as to expose the needle tip, 3) there is chance that blood on or near the needle tip may surface out of the needle guard because the needle is still exposed from the sides and because the size of the needle guard is too small with respect to the portion of the needle needing to be covered.
In other prior art references such as U.S. Pat. No. 6,117,108, the safety device remains inside the main body of the catheter apparatus. However, because of the miniature size of the main body there remains a strong probability of blood coming out of the safety device and infecting the persons handling the used needle.